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Indexed by:期刊论文

Date of Publication:2011-02-02

Journal:CATALYSIS TODAY

Included Journals:Scopus、SCIE、EI

Volume:160

Issue:1

Page Number:179-183

ISSN No.:0920-5861

Key Words:Shape-selective; Nano-scale HZSM-5; Pt; Hydrogenation; Stability

Abstract:Shape-selective methylation of toluene (T) with methanol (M) was carried out in continuous flow fixed-bed reactor over Pt-modified nano-scale HZSM-5 catalysts, and excellent stability was obtained. Even after 500 h on stream, toluene conversion of 22.0-23.0% was achieved simultaneously with the para-selectivity of >98%. The presence of Pt on the modified nano-scale HZSM-5 solves the apparent paradox of high para-selectivity and low stability. Catalysts were characterized by using X-ray diffraction (XRD), temperature programmed desorption of ammonia (NH(3)-TPD), Pyridine IR (Py-IR), TG-SDTA, scanning electron microscope (SEM), etc. The results show that significant enhancement in stability over Pt-modified nano-scale HZSM-5 catalysts is mainly due to good hydrogenation properties of Pt particles. (C) 2010 Elsevier B.V. All rights reserved.